Ok...I am almost positive this works on an '05. I know it worked on 99-03, so I don't see why not.
Take the top and bottom of the steering column cover off, then take your key and put it in the ignition turning it to run (not start). Reach in with a allen key/pen/etc from underneath the column to release the ignition cylinder and pull it out. There is a wire with a "springy" piece of metal that when grounded sets off the dinger. Just pull it out (towards the passenger door) and tape it off so it can't ground out and put it inside the column out of the way. I can't remember if that wire is black or brown, you can probably find it on a search.
If you know how to do it, it takes about 30 seconds to a minute to do and it only gets rid of the door dinger for the key in the ignition with the door open. Lights on with the truck off will still ding to remind you to turn them off.
If I was at home I could take mine apart real quick and take some pictures. Best mod I've done to mine....Can sit with the door open and listen to the radio when I'm working.